Removal of metals from oleaginous materials and analysis of the metals



United States Patent U.S. Cl. 23-230 29 Claims ABSTRACT OF THE DISCLOSURE A method and composition for removing metal contaminants, such as metallic iron and the like, from oleaginous materials, particularly helicopter gear box oils, and determining the relative quantity of the removed metal, including mixing all or a part of the oil with a carrier liquid, which is immiscible with the oil so as to form two separate liquid phases, for example an oil phase and an anhydrous diethylether phase, and a solubilizing composition capable of converting the metal in question to a form having a substantial affinity for the carrier liquid, for example hydrochloric acid to convert metallic iron to ferrous chloride and hydrogen peroxide to oxidize the ferrous chloride to ferric chloride which is soluble in the diethylether phase, separating the carrier liquid containing the solubilized metal contaminant from the oil, filtering the carrier liquid to remove oil droplets therefrom, preferably adding a second portion of the solubilizing composition to separate any residual oil, again filtering the carrier layer and washing with distilled water, and analyzing the resultant liquid for the metal in question, as by adding a color indicator, such as 1,10-phenanthroline, and measuring the intensity of the resultant color against a standard.

The present invention relates to a method and composition for removing metallic components from an oleaginous material. In a more specific aspect, the present invention relates to a method and compositioin for the removal of metallic components from an oleaginous material of lubricating oil viscosity. In an even more specific aspect, the present invention relates to a method for analyzing oleaginous materials of lubricating oil viscosity to determine the content of a predetermined metallic component.

Oleaginous materials have long been used as lubricants for relatively moving metal parts. While present-day lubricants have been improved to the point where excellent lubrication is obtained, there are still certain unavoidable actions and reactions which take place in the use of a lubricant which reduce the effectiveness of the lubricant and contribute to the wear of the moving parts. One of the most significant factors contributing to the wear of the moving parts is the contamination of the lubricant by metallic components, generally originating in the lubricated part itself. For example, wear of the relatively moving parts causes minute particles of the metal to be deposited in the lubricant; in some cases, corrosion causes metallic corrosion products to be deposited in the lubricant; and the formation of compounds, which chemically react with the moving parts, also is responsible for depositing metallic compounds in the lubricant. These metallic components, in most cases, reduce the effectiveness of the lubricant and, in some cases, contribute to the Wear and damage of the moving parts. This is particularly true where the metallic components are present as minute solid particles of an abrasive character, and is true even though these abrasive materials are present in what would normally be considered trace amounts.

The presence of small amounts of abrasive materials in lubricants becomes particularly critical where the lubri- "ice cant is used under heavy-duty conditions, or conditions where the relatively moving parts are under extreme strains. One such extreme environment is the gear box of a helicopter. In the lubrication of helicopter gear boxes, the presence of contaminants and, particularly, abrasive contaminants becomes quite critical because of the extreme strains placed upon the gears. Often, small amounts of the abrasive material left in a helicopter gear box for a relatively short period of time will cause destruction of gear box elements, either by actual grinding up of the elements, or failure of lubrication, causing freezing together or welding together of the elements. The consequences of such failure are so obvious as to require no illustration, particularly if the helicopter is to be used in military operations. Because of the criticality of the abrasive metal content of helicopter gear box lubricants, the military requires frequent sampling and analysis of such lubricants for metal components, in particular, elemental iron particles. While such frequent sampling and analysis is effective in reducing failures of the gear boxes in use, the methods presently available for carrying out the analysis make it impossible to efiiciently schedule and carry out the tests.

Conventionally, the determination of inorganic or metal content of an oil consists of burning the oil sample freely in an open tared dish and subsequent ignition of the residual coke to obtain a residual ash. The weighed ash is then subjected to chemical analysis to determine the content of individual components. This is a tedious procedure requiring a high degree of skill and it requires very large samples of oil to produce sutficient ash for analysis.

Also, at the present time, military requirements have approved only one method of analyzing helicopter gear box oils for elemental iron, and this is the spectrographic analysis of an oil sample. As is well known, spectrographic analysis involves spark excitation of an electrode impregnated with the oil sample. Generally, the electrode is a carbon electrode of one form or another, which is either impregnated with the oil in situ in the gear box, or by a sample of oil taken from the gear box. This preparation of the oil sample for spectrographic analysis is, in itself, a rather tedious and unwieldy operation. However, this is only a small part of the real problem involved in spectrographic analysis, the major problem being that the spectrographic analysis itself must be carried out in complex, delicate laboratory equipment, and there are only a very few such installations in the United States. Consequently, it is the practice of the military to sample helicopter gear oils in the field and fly these samples to one of the several testing laboratories for analysis. The ditliculties, inefficiencies and expense of this operation are quite numerous. Such an operation often requires that the helicopter be taken out of service until the test results can be obtained, or be retained in service even though the metal content of the lubricant may have reached a dangerous amount because of abnormal conditions. To some extent, the testing can be made sutficiently frequent to overcome these delays and difficulties, and the lubricant can be changed at sufficiently frequent intervals that the chances of actual failure of a gear box are rather remote. However, these expedients are already being practiced and yet such failures do occur. The ultimate fact is that none of these expedients is a substitute for a field test technique which can be carried out in a field office or even at the helicopter location by non-technical personnel. Prior to the present invention, no such simple field testing procedure has been known.

While a large number of methods for the qualitative or quantitative determination of the content of metals in various materials exist, and some of these techniques are sufficiently simple and non-critical to permit non-technical personnel to carry out, the prior discussion indicates that the predominant methods of analyzing oleaginous materials for metal content have one major drawback. It is to be noted that in the most frequently employed methods for detecting and measuring the metal content of oleaginous materials, the oil sample must either be destroyed and the ash remaining thereafter analyzed, or the metal content analyzed in the presence of the oil. These techniques, of course, require highly skilled technical personnel to conduct the test and, as previously indicated, the test must ultimately be carried out in the laboratory where close control can be exercised. It can readily be appreciated that a simple analytical procedure, such as, colorimetric analysis, would be highly desirable if this type test could be used. As is well known, such colorimetric analysis involves the use of certain chemicals which give characteristic color indications when they form complexes or other combinations with a particular metal. The resultant colored material may thereafter be simply compared with a set of standard materials, or the intensity of the color can be measured with a simple colorimeter. Unfortunately, there has heretofore been no known technique or indicator workable in the presence of an oleaginous material and, in addition, there has been no known'technique for the removal of metal components from oleaginous materials for subsequent analysis by colorimetry or like techniques. In addition, such removal and recovery of metallic components from oleaginous materials is multiplied many fold when one is dealing with extremely small amounts of the metallic components in a large volume of lubricant.

It is therefore an object of the present invention to provide an improved method and composition for removing metallic components from an oleaginous material.

Another object of the present invention is to provide an improved method and composition for removing a preselected elemental metal from an oleaginous material.

Still another object of the present invention is to provide an improved method and composition for the removal of iron from an oleaginous material.

A further object of the present invention is to provide an improved method and composition for removing at least one metallic component from an oleaginous material of lubricating oil viscosity.

Another and further object of the present invention is to provide an improved method and composition for removing iron particles from used helicopter gear box oils.

A still further object of the present invention is to provide an improved method for detecting the presence of at least one metallic component in an oleaginous material.

Another object of the present invention is to provide an improved method for measuring the quantity of at least one metallic component present in an oleaginous material.

Another object of the present invention is to provide an improved method for detecting and measuring the quantity of at least one metallic component present in an oleaginous material.

A further object of the present invention is to provide an improved method for detecting and measuring the quantity of a preselected metal present in an oleaginous material of lubricating oil viscosity.

Still another object of the present invention is to provide an improved method for detecting and measuring the quantity of a preselected metal in an oleaginous material which can be performed in field locations.

A further object of the present invention is to provide an improved method of detecting and measuring the quan tity of a preselected metal in an oleaginous material which can be carried out by non-technical personnel.

Another and further object of the present invention is to provide an improved method for detecting and measuring the quantity of a preselected metal in helicopter gear box oils.

Another object of the present invention is to provide an improved method for detecting and measuring the quantity of iron in helicopter gear box oils.

Still another object of the present invention is to provide and improved method of lubricaing helicopter gear boxes.

These and other objects and advantages of the present invention will be apparent from the following detailed description of the present invention.

Briefly, in accordance with the present invention, it has been found that metallic components can be removed from oleaginous materials by adding to the oleaginous material a carrier liquid, which is immiscible with the oleaginous material, and a solubilizing composition capable of converting the metallic components to a form having a substantial aflinity for the carrier liquid; and, thereafter, separating the carrier liquid containing solubilized metallic components from the oleaginous material layer. The metallic components present in the separated carrier liquid may then be subjected to analysis to detect the presence of one or more metallic components and, if desired, the quantity of such metal which is present in the lubricant. Preferably, the analysis is a simple analytical technique, which can be performed by non-technical personnel, such as colorimetric analysis.

The method of removing metals from oleaginous materials, as set forth above, is effectively carried out by the use of a novel metal removing composition, including a solubilizing composition and a carrier liquid, as set forth hereafter in detail.

The previously-mentioned step of utilizing a solubilizing composition to convert the preselected metallic component to a form which has a substantial aifinity for the selected carrier fluid may consist of a two-step or a singlestep operation involving the use of a solubilizing composition of one or more ingredients. As is quite obvious, the solubilizing composition and the carrier liquid are interrelated.

The term immiscible as used in the present application is meant to include a liquid which forms a separate and distinct phase when admixed with an oleaginous material. In this connection, it is to be recognized that immiscible liquids can form two separate and distinct layers, one may be in the form of drops distributed throughout the other, or the two phases may assume various other forms. All such forms are meant to be included herein, provided, only, that the two phases may be separated by mechanical means, such as, decantation, filtering, centrifuging, etc. Where the phrase afiinity for the carrier liquid is employed, this phrase is used herein to indicate that the material in question will preferably combine with the carrier liquid in preference to the oleaginous material. Accordingly, this term is meant to include concentration of the material in question in the carrier liquid, whether such concentration is due to chemical combination with the carrier liquid, solubility or solution in the carrier liquid, or emulsification or dispersion in the carrier liquid.

Since any number of materials may be employed as a carrier, the most important factor, therefore, becomes the selection of the solubilizing composition. In the majority of cases, it has been found that bi-valent metallic components can best be solubilized by changing the valence of the metal by chemical conversion or otherwise. In other words, where a particular metal is present in an oleaginous material in one valence form, it will generally exhibit an affinity for the oleaginous material in that particular form. On the other hand, if the metal is changed to a higher or lower valence form, it can be rendered substantially more soluble in a carrier liquid and less soluble in the oleaginous material. In other instances, the valence form in which the metal exists in the oleaginous material may not have any significant affinity for the oleaginous material, but it may also be difficult or impossible to find a carrier liquid for which metallic compounds of that particular valence form will have an afiinity. However, in these cases also, a change in the valence of the metal will quite often be effective in solubilizing the metal in a carrier liquid. Obviously, this increase or decrease in the valence of a metal can be brought about by including in the solubilizing composition an oxidizing or a reducing agent. As a specific example of the above, iron may be present in a lubricating oil in its elemental form, or as a ferrous compound. In this form, it is difficult to extract the iron from the lubricant by means of a suitable carrier liquid. However, if the iron is converted from the ferrous to the ferric form, it will be soluble in various carrier liquids and can thus be separated from the oil in such a carrier.

In some instances, when the metal is in the form of solid particles as, for example, solid particles of elemental iron, it is necessary to include in the solubilizing composition a material capable of dissolving the metal particles. For example, iron particles may be readily dissolved by treatment with hydrochloric acid to produce ferrous chloride. The ferrous chloride may, as previously pointed out, be converted to ferric chloride by treatment with an oxidizing agent, such as hydrogen peroxide, sodium peroxide, potassium permanganate and the like. The initial dissolution of the iron and its subsequent solubilization may, of course, be carried out in a two-step operation, or, preferably, simultaneously by the use of the improved metal removing composition of the present invention.

The carrier liquid employed, in accordance with the present invention, must be selected on the basis of its immiscibility with the oleaginous material. As previously indicated, any number of known carrier liquids which are immiscible with oleaginous materials can be employed. The second requirement of the carrier liquid is, of course, its ability to preferentially absorb the solubilized metal composition. In the example previously employed, where iron is the preselected metal, iron in the ferric form can be selectively removed by utilizing materials, such as, diethyl ether, di-isopropyl ether, isobutyl methyl ketone, amyl alcohol, a chloroform solution of isonitrosoacetophenone, etc. The carrier will, of course. also depend upon whether the solubilizing composition contains another ingredient, such as hydrochloric acid. If, on the other hand, the solubilizing composition includes a reducing agent to convert iron to the ferrous form, carrier liquids, such as, amyl alcohol, ethyl acetate, chloroform and the like may be used.

Having converted the metallic component selected to a form in which it is soluble in the immiscible carrier liquid by the use of the metal removing composition or by other means, the mixture of carrier liquid and oleaginous material is permitted to separate into the carrier liquid layer, containing the preselected metal, and an oleaginous material layer. The carrier liquid layer may be drawn off or separated from the oleaginous material layer by any one of a number of known techniques.

Having now removed the metallic component from the oleaginous material one is permitted to carry out any one of a number of subsequent operations on the metallic component. Specifically, one may quantitatively or qualitatively measure the preselected metal component. Since the oleaginous material is no longer present to interfere with more simple analysis techniques, a technique may be chosen which is quite simple and which can be carried out by non-technical personnel. The preferred test in accordance with the present invention is the colorimetric detection or measurement of metal content. This technique can be utilized simply by selecting a proper indicator and adding this indicator to an aqueous solution containing a metallic component. By forming a chemical compound or a complex with the metal in question, these indicators change the color of the solution to a characteristic color. In addition, many of these indicators produce a color change which lasts for several months, or even a year, without fading or changing and also following Beers Law closely, and thus having a color intensity which is directly proportional to the quantity of the metal in solution. By comparing the colored solution with standard solutions or other color standards, un-

skilled non-technical personnel can readily complete the test. Also, the color intensity can be measured in a conventional colorimeter to produce a numerical indication which can be compared with standard numerical values.

The number of indicator chemicals which can be em ployed in colorimetric analysis is quite voluminous and, therefore, no effort will be made to mention all or a substantial portion thereof. However, several representative materials which have been used and have been found effective as iron indicators will be mentioned. Where iron is in the ferric state, the most conventional indicator is thiocyanate. However, there is a tendency for the resultant color to fade in the absence of other reagents. Other effective indicators are: mercaptoacetate, 8-hydroxyquinoline, acetyl-acetone and the like. Preferably, however, the iron should be reconverted to the ferrous form, since more elfective and more stable indicators are available for ferrous iron. Preferably, the indicators are organic heterocyclic compounds containing the group:

Suitable indicators include: 1,10-phenanthroline; 2,2'-bipyridine; 4,7-diphenyl-1,IO-phenanthroline; 2-(2-pyridyl)- irnidazoline; dimethylglyoxime+pyridine; and like materials.

In the example given, it has been indicated that the ferric iron separated from the oleaginous material should be reduced in valence to its ferrous form prior to colorimetric analysis. This operation is preferably performed by the addition of a reducing agent, such as, hydroxylamine hydrochloride, hydroquinone, or other organic reducing agents. By utilizing hydroxylamine hydrochloride, the hydrogen peroxide used as an oxidizing agent is also reduced by the hydroxylamine hydrochloride and the heat of reaction drives the ether off as a gas. This, then, leaves the iron to react with the indicator material in an aqueous solution. After reaction, excess hydrochloric acid may be neutralized with ammonium hydroxide.

The same general procedures, previously outlined, for the removal of iron from oleaginous materials are applicable to other multi-valent metals. Specifically, oxidation to a higher valence compound, which is soluble in one of the generally known immiscible solvents, may be utilized for the removal of metals such as arsenic, antimony, copper, chromium, tin and the like.

Oleaginous materials from which metals can be removed by the method and composition of the present invention, include all of the known oleaginous materials, particularly those of lubricating oil viscosity, such as, natural mineral oil; vegetable and animal oil fractions; and synthetic oils, such as, olefin polymers, for example, polybutenes, polypropylene and mixtures thereof, oils of the alkylene-oxide type; for example, the Ucon oils, marketed by Carbide and Carbon Corporation, polycarboxylic acid ester-type oils, for example, esters of adipic acid, maleic acid, etc., liquid esters of phosphorous, polymers of silicons, and like liquids.

The following specific example is given to show the details of the procedure employed in the preferred method of the present invention, as applied to the determination of iron in MIL-L-6082 grade (1065) transmission oil.

A sample of the oil, somewhat larger than the amount ultimately tested, is withdrawn from the gear case of a helicopter. Such withdrawal or sampling should, of course, be conducted at predetermined regular intervals. Before measuring the sample to be tested, the sample removed from the gear box should be stirred vigorously to insure uniformity. After thorough stirring and shaking, 6 milliliters of the oil are measured (weighing 5 grams) in a graduated cylinder and transferred to a 250 milliliter separatory funnel.

The removal of the iron by treatment is with a metal removing composition comprising 10 ml. of 1:1 hydrochloric acid, 10 ml. of 1:1 30% hydrogen peroxide and of 10 m1. of anhydrous diethyl ether. In general, the

amount of hydrochloric acid employed should be slightly in excess of the amount required to react with the anticipated amount of iron to form ferrous chloroide, the amount of hydrogen peroxide should be slightly in excess of that required to convert the ferrous chloride to ferric chloride and the amount of diethyl ether should be sufficient to form a readily separable, distinct ether-acid layer. While the sequence of adding the particular treating agents of the novel composition is not critical, the following sequence is preferred: 10 milliliters of anhydrous diethyl ether are measured in the same graduated cylinder previously used to measure the oil sample and transfer it to the separatory funnel. The ether serves to rinse out the remainder of the oil from the graduated cylinder. Then the 10 milliliters of hydrochloric acid are measured in the same cylinder and placed in a separatory funnel. Finally, the 10 milliliters of hydrogen peroxide are measured and poured into the funnel. The resultant mixture is perfectly safe when handled correctly, the operator being careful only to avoid smoking in the vicinity of the mixture or bringing the mixture too close to a flame. The mixture of carrier liquid and solubilizing composition and oil is then shaken vigorously for about minutes, being careful to release the pressure several times in the beginning. The ether-acid layer is then separated and filtered through a #40 Whatman paper into a 150 ml. beaker. The filtering is performed in order to remove any oil droplets which may be present in the ether-acid layer. A second portion of the solubilizing composition, containing equivalent amounts of agents ml. hydrochloric acid and 10 ml. of hydrogen peroxide), is then added to the oil remaining in the separatory funnel. It is to be noted that in this case the ether is omitted. As in the previous treatment with solubilizing agent, the mixture is shaken vigorously and the acid layer separated and filtered as above. The pressure, of course, should be released, as previously indicated. Thereafter, 5 ml. of 30% hydrogen peroxide and 10 ml. of a distilled water are added to the oil in the separatory funnel and shaken. After several minutes, 5 ml. of concentrated hydrochloric acid is added and the resultant mixture is shaken for about 5 minutes while releasing the pressure on occasion. In this particular instance, it appears necessary to add the hydrogen peroxide separately in order to decrease the acidity of the mixture and obtain better oxidation of the iron. The separated acid layer is then filtered through the same filter paper and washed with distilled water in two steps, utilizing 5 ml. of water in each washing step.

The procedure set forth above has proven highly effective in the removal of small amounts of iron from a lubricating oil, even when the iron is present in trace amounts. It should also be noted that the procedure and materials used do not require that a technically trained person perform the operation. Thus, it is clear that a simple and elfective method of separating metals from oleaginous materials, which can be performed in field locations, has been provided. It will be obvious to one skilled in the art that the separated metal may be treated in a number of ways or utilized for a number of purposes. However, in the preferred technique of the present invention, the separation is performed for the purpose of subsequently obtaining a quantitative measure of the amount of iron present in the lubricating oil.

The first step, in the preferred method of quantitatively measuring the iron content, is to add a reducing agent to convert the iron to its ferrous state. Specifically, 2 grams of solid hydroxyamine hydrochloride is slowly added, with stirring, to the iron-containing solution. In addition to reducing the valence of the iron, the reducing agent also acts to react with the hydrogen peroxide present in the mixture, and by this reaction generates heat which drives off the ether. Reasonable care is required in this step, since a strong reaction and heat is produced.

The colorimetric analysis of the iron-containing solution is then carried out. 10 ml. of 0.1% 1,10-phenanthroline is added to the beaker. An orange colored solution is produced. In order to neutralize the hydrochloric acid present in the solution, 16 ml. of concentrated ammonium hydroxide are added. The pH of the solution should be checked with all range pH paper and the pH adjusted by the addition of concentrated ammonium hydroxide or concentrated hydrochloric acid in dropwise fashion. A pH range of 4-6 has been found desirable in obtaining a colored solution which does not change in intensity. The correct pH range can also be checked by the addition of concentrated ammonium hydroxide until no color change occurs. The solution is then transferred to a ml. volumetric flask, the beaker is rinsed with a small amount of distilled water which is added to the flask and diluted to form 100 milliliters of solution. Maximum color intensity develops in about 10 minutes and the resultant color is stable for 6 months to a year.

The above colorimetric procedure can, of course, be utilized alone as a qualitative indication of iron content. If a quantitative measure is desired, the solution should be transferred to a color comparison tube. The amount of iron is then measured by reading the absorbance scale of a colorimeter. This reading is then compared with colorimeter values for known iron standards. The procedure can be simplified by referring the absorbance value to a standard absorbance-iron content curve. Alternatively the colors can be compared against iron standards contained in color comparison tubes. This, of course, is a simple procedure where a colorimeter is not available. In addition, where some known maximum critical concentration of iron is a determining factor, a single standard solution in a color comparison tube can be utilized in order to simplify the procedure even further.

In order to obtain the iron concentration in parts per million in the oil sample, the parts per million of iron obtained from the absorbance-iron content curve is multiplied by a constant 20. This, of course, is based upon the utilization of a 5 gram sample of oil. Accordingly, if a 10 gram sample is employed, the constant would be 10. Obviously, with other size samples, other multiplying constants would be used.

From the above example, it is to be seen that an effective method of determining iron in helicopter transmission lubricating oils has been provided which does not require extensive laboratory equipment. Without a test of the character provided herein, it has been necessary in the past to arbitrarily replace the dynamic parts of helicopter transmissions at given time intervals without any real knowledge of the actual performance of the parts and irrespective of the condition they are in. This obviously increases the expense of maintenance far beyond what actual conditions of use may require. In addition, it has, in the past, been virtually impossible to get an accurate and realistic time schedule for overhaul and maintenance, since there is no way to determine what the actual life of the parts is in the given piece of equipment in which they are used. Finally, the technique of the present invention permits one to detect premature failures of transmission parts at an early stage, thereby permitting the transmissions to be overhauled before such premature failure takes place. This, of course, is an extremely important safety feature.

Having described the present invention and illustrated its application by way of specific example, it is to be understood that such examples are illustrative only and modifications and variations which do not depart from the basic invention, will be apparent to those skilled in the art. Accordingly, the present invention -is to be limited only in accordance with the appended claims.

I claim:

1. A method for removing at least one metallic component from an oleaginous material comprising:

(a) adding to said oleaginous material a carrier liquid immiscible with said oleaginous material;

(b) at least a part of said metallic component being initially insoluble in said carrier liquid;

(c) adding to the mixture of oleaginous material and carrier liquid a solubilizing composition capable of converting said metallic components to a form having a substantial affinity for said carrier liquid; and

(d) separating said carrier liquid containing said converted metallic components from said oleaginous material.

2. A method in accordance with claim 1 wherein the metallic component is a metal in elemental form.

3. A method in accordance with claim 1 wherein the metallic component is elemental iron.

4. A method in accordance with claim 1 wherein the oleaginous material is a lubricant.

5. A method in accordance with claim 1 wherein the oleaginous material is an organic lubricant.

6. A method in accordance with claim 1 wherein the oleaginous material is an organic composition of lubricating oil viscosity.

7. A method in accordance with claim 1 wherein the carrier liquid is an organic liquid immiscible with the oleaginous material.

8. A method in accordance with claim 1 wherein the metallic component comprises solid particles of metal in elemental form and the solubilizing composition includes a material capable of converting said solid particles to a compound of the elemental metal and a material capable of converting said compound to a metal compound of different valence soluble in the carrier liquid.

9. A method in accordance with claim 8 wherein the metallic component is elemental iron and the solubilizing composition includes hydrochloric acid and hydrogen peroxide.

10. A method in accordance with claim 1 wherein the metallic component is elemental iron, the solubilizing composition includes an oxidizing agent and the carrier liquid is diethyl ether.

11. A method in accordance with claim 1 wherein the metallic component is elemental iron, the carrier liquid is diethyl ether and the solubilizing composition includes hydrochloric acid and hydrogen peroxide.

12. A method in accordance with claim 1 wherein the carrier liquid is separated by removing a layer of said carrier liquid from a layer of the oleaginous material.

13. A method in accordance with claim 1 wherein the solubilizing composition is capable of converting the metallic component to metallic components having a different valence.

14. A method in accordance with claim 13 wherein the solubilizing composition is a material capable of oxidizing the metallic component to a higher valence material.

15. A method in accordance with claim 14 wherein the metallic component is iron and the solubilizing composition includes hydrogen peroxide.

16. A method for removing at least one metallic component from an oleaginous material, comprising:

(a) adding to said oleaginous material a metal removing composition, including a carrier liquid immiscible with said oleaginous material;

(b) said metal removing composition having a substantial affinity for said metallic components; and

(c) separating said carrier liquid containing said metallic component from said oleaginous material.

17. A method for determining the content of at least one metallic component in an oleaginous material comprising:

(a) adding to' said oleaginous material a metal removing composition, including a carrier liquid immiscible with said oleaginous material;

(b) said metal removing composition having a substantial afiinity for said metallic component;

(c) separating said metal removing composition containing said metallic component from said oleaginous material; and

(d) analyzing said metal removing composition for said metallic component.

18. A method in accordance with claim 17 wherein at least a part of said metallic component is initially insoluble in said metal removing composition and said metal removing composition includes a solubilizing composition capable of converting said metallic component to a form having a substantial afiinity for said carrier liquid.

19. A method in accordance with claim 17 wherein the step of analyzing includes colorimetric analysis.

20. A method in accordance with claim 19 wherein 1,10-phenanthroline is utilized as a color indicator.

21. A method in accordance with claim 17 wherein the metallic component is iron, the solubilizing composition includes an oxidizing agent to convert said iron from its ferrous to its ferric form, and the analyzing step includes treating the converted metallic component with a reducing agent to reconvert it to its ferrous form after separation from said oleaginous material.

22. A method in accordance with claim 21 wherein the metal removing composition includes hydrochloric acid and hydrogen peroxide and the analyzing step includes treating the converted metallic component with hydroxylamine hydrochloride and the utilization of 1,10-phenanthroline as a color indicator.

23. A metal removing composition for removing at least one metallic component from an oleaginous material, comprising:

(a) a non-aqueous, carrier liquid immiscible with said oleaginous material, which carrier liquid is not a solvent for at least a part of said metallic component; and

(b) a solubilizing component capable of converting said metallic component to a form having a substantial aflinity for said carrier liquid.

24. A composition in accordance with claim 23 wherein the solubilizing composition includes a material capable of changing the valence of said metallic component.

25. A composition in accordance with claim 23 wherein the metallic component is a solid particle of metal in elemental form and the solubilizing component includes a material capable of dissolving said solid particles and a material capable of changing the metallic component to a form having different valence.

26. A composition in accordance with claim 23 wherein the solubilizing component includes an oxidizing agent.

27. A composition in accordance with claim 23 where in the solubilizing component includes hydrochloric acid and hydrogen peroxide.

28. A composition in accordance with claim 23 wherein the carrier liquid is diethyl ether and the solubilizing component includes hydrochloric acid and hydrogen peroxide.

29. A method of lubricating helicopter gear boxes, and analyzing for metallic components in the lubricant, comprising:

(a) maintaining in said gear box an oleaginous material of lubricating oil viscosity;

(b) periodically removing a sample of said oleaginous material from said gear box;

(c) adding to said sample of oleaginous material a metal removing composition, including a carrier liquid immiscible with said oleaginous material;

(d) said metal removing composition having a substantial aflinity for at least one metallic component;

(e) separating said metal removing composition containing said metallic component from said oleaginous material; and

(f) analyzing said metal removing composition for said metallic component.

(Other references on following page) OTHER REFERENCES MORRIS O. WOLK, Primary Examiner.

Forrester et a1., Rapid Chemical Determination of R. E. SERWIN, Assistant Examiner. Iron, Nickel, and Vanadium in Petroleum Oils, Analyt- U S Q X R ical Chemistry, vol. 32, N0. 11, pp. 1443-1446, October 1960. 5 233 12; 210-21, 59; 252-364 

